The present invention relates to an air cleaner and, more particularly, to a cyclone type air cleaner for cleaning air be separating dust particles and other foreign matters from air by making use of centrifugal force.
As is well known to those skilled in the art, a cyclone type air cleaner is constructed such that the air suspending dust particles and other foreign matters (referred to as "contaminated air" hereinunder) is introduced into a cylindrical housing defining a swirling chamber is caused to flow through the swirling chamber while swirling so that the dust particles and other foreign matters are separated from the air by the centrifugal force. In order to increase the centrifugal separation effect, therefore, it has been necessary to increase the size and, particularly, the axial length or height of the housing.
On the other hand, there is an increasing demand for reduction in size and weight of the air cleaners. To comply with this demand, it is necessary to reduce the size and, particularly, the height of the cylindrical housing. The reduced size of the cylindrical housing, however, undesirably impairs the swirling action and, hence, the centrifugal separation effect, resulting in a lowered dust separation efficiency to heavily burden an air filter element dispased in the downstream end of the housing as viewed in the direction of the flow of air.